Retro68/gcc/newlib/libc/machine/arm/aeabi_memmove-thumb2.S
2017-10-07 02:16:47 +02:00

66 lines
2.0 KiB
ArmAsm

/*
* Copyright (c) 2015 ARM Ltd
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
.thumb
.syntax unified
.global __aeabi_memmove
.type __aeabi_memmove, %function
ASM_ALIAS __aeabi_memmove4 __aeabi_memmove
ASM_ALIAS __aeabi_memmove8 __aeabi_memmove
__aeabi_memmove:
cmp r0, r1
push {r4}
bls 3f
adds r3, r1, r2
cmp r0, r3
bcs 3f
adds r1, r0, r2
cbz r2, 2f
subs r2, r3, r2
1:
ldrb r4, [r3, #-1]!
cmp r2, r3
strb r4, [r1, #-1]!
bne 1b
2:
pop {r4}
bx lr
3:
cmp r2, #0
beq 2b
add r2, r2, r1
subs r3, r0, #1
4:
ldrb r4, [r1], #1
cmp r2, r1
strb r4, [r3, #1]!
bne 4b
pop {r4}
bx lr
.size __aeabi_memmove, . - __aeabi_memmove